[EGD-5737] Merge master into experimental

Keep experimental up to date with changes from master

[EGD-5334] Fix phone crash when MTP access

Fix phone crash when accessing file when new filesystem is used

[EGD-5737] Merge master into experimental

Keep experimental up to date with changes from master

[EGD-5014] Add eMMC block device API

Add PureOS wrapper for eMMC driver with support
for basic block device operations.

[EGD-5737] Merge master into experimental

Keep experimental up to date with changes from master

[EGD-5102] Fix compile on rt1051 platform

It is initial commmit which fix compilation after
vfs. global object removal. It still need implementation
newlib syscalls.

[EGD-5102] Fix warning errors in the BSP

Fix warning errors in the BSP module

[EGD-5088] Change new filesystem implementation

Removed deprecated vfs calls from all applications.

[EGD-5346] Refactor of battery charger BSP

Pure refactoring of battery charger to privide compliance
 with modern C++ standards. Done before implementation of
battery charging algorithms.

Merge branch 'master' into stable

[EGD-5086] Fix voice not starting when calling

Due to a race condition between source and sink voice is not always
starting when calling. Introduce audio stream connections to avoid
race condition and improve handling of audio start and stop operations.

Signed-off-by: Marcin Smoczyński <smoczynski.marcin@gmail.com>

[EGD-4887] Add PLL2 clock switching

Pll2 will be disabled at the lowest CPU frequency,
which will save power

[EGD-5086] Change audio device switching logic

Upon hardware change event, audio profile had been switched multiple
times forcing redundant initializations of all related objects. Logic
has been optimized and prepared for further refactor. Now upon hardware
event objects are initialized exactly once.

[EGD-5078] Fix Debug UART conditional enabling

Uart debug will be enabled only when redirecting logs to Uart

[EGD-4881] Add oscillator clock switching mechanisms

Osc will change automatically at the lowest CPU frequency,
which will save power

[EGD-5050] Add brownout detection

Brownout detectection realized through charger driver

[EGD-5061] Fix lack of audio during call

Audio might have not work if audio streams
were reused. This was fixed by introducing proper
cleaning procedures.

[EGD-5004] Add USB-CDC echo mechanism

Added echo mechanism to USB-CDC, update usb_stack submodule
and added a test case to test harness

[EGD-4694] Add CPU frequency shift mechanism

The CPU frequency changes automatically which saves energy

[EGD-5036] Change new filesystem

Due to vfs deprecation there is need
to remove all vfs calls from code.
This PR covers module bsp.